1. Field
This disclosure relates to solid fuel rocket motors, and particularly to cartridge-loaded solid fuel rocket motors.
2. Description of the Related Art
Solid fuel rocket motors are commonly used in various configurations to propel rockets and missiles. Small solid fuel rocket motors may also be used to control the attitude and steering of a missile, rocket, or other projectile. Small solid fuel rocket motors used to control attitude are commonly called divert thrusters. Solid fuel rocket motors may also be used to turn a vertically-launched missile or rocket into near-horizontal flight. Such rocket motors are commonly called pitch-over thrusters.
The thrust or force produced by a rocket motor is given by the equationF=mp*Ue+(Pe−Pa)*Ae                 where                    mp=propellant mass flow rate, and            Pe=Nozzle exit pressure            Pa=Ambient pressure            Ae=Nozzle exit area            Ue=gas velocity at nozzle exit plane.                        
The propellant mass flow rate mp is given by the equationmp=Ap*Rb*Pp                 where                    Ap=propellant surface area,            Rb=propellant burn rate, and            Pp=propellant density.                        
Thus the propellant surface area Ap is one of the factors that may be used to determine the thrust produced by a solid fuel rocket.
The force produced by a rocket motor results in a linear or angular acceleration of the missile or other body propelled by the rocket motor. The net change in the linear or angular velocity of the missile or other body is proportional to the force produced by the motor integrated over time. The time integral of the force produced by a rocket motor is commonly called the “impulse” of the motor.
Throughout this description, elements appearing in figures are assigned three-digit reference designators, where the most significant digit is the figure number and the two least significant digits are specific to the element. An element that is not described in conjunction with a figure may be presumed to have the same characteristics and function as a previously-described element having a reference designator with the same least significant digits.